+P (thing)

A designation used to indicate a cartridge that is loaded to significantly higher pressures, hence greater velocities, than the original cartridge. A "+P" designation means that the external dimensions are identical to that of the original, different from "Magnum" which usually means a longer cartridge with greater case capacity. +P+ rated ammo are loaded to even higher pressures than +P.

Before trying to shoot +P rated ammunition in your firearm, first verify that it is rated for use with these higher pressure rounds. Most modern firearms can handle +P loads, but at the cost of accelerated wear. Although not very likely, the use of +P rated ammo in firearms that were not designed for it can result in a case failure which can lead to aKaBoom! or Kb!.